Blading and lining for turbines.



G. E. SWEET.

BLADING AND LINING POR TURBINES.

APPLIOATION FILED JUNE 25. 190s.

997,216. n Patented July 4,1911.

Y QQMMSSKWOR' B eswAT RNEYIN FACT.

UNITED STATES PATENT OFFICE.

CHARLES E. SWEET, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR, BY MESNE AS-SIGNMENTS, T0 THE COLONIAL TRUST COMPANY, TRUSTEE, 0F PITTSBURG, PENN-SYLVANIA, A CORPORATION OF PENNSYLVANIA.

BLADING AND LINNG FOR TURBINES.

To all whom it may concern:

Be it known that I, CHARLES E. SWEET, a citizen of the United States,and a resident of Villinsburg, in the county of Allegheny and State ofPennsylvania, have made a new and useful nvention in Blading andProtective Linings for Turbines, of which the following is aspecification.

This invent-ion relates to elastic fluid turbines and has for an objectthe production of simple and effective means for blading the turbinesand for providing a protective covering for the blade-carrying elementsof turbines.

The corrosive and erosive action encountered in elastic fluid turbinesvmay result from chemical impurities in the boiler feed water, such, forinstance, as organic or inorganic acids, or it may result from thecorrosive action of the distilled water, that is, the water ofcondensation, and the erosivc action of the motive Huid and the water ofcondensation. lVhatever the cause, the fact remains that the exposedsurfaces of the blade-carrying elements are at times corroded and evenbadly pitted. The cast iron casing of the turbine (the stationarybladecarrying element) is usually more actively attacked and for thisreason the primary object of my invention is to provide a protectivelining for the casing, but l desire it to be understood that lcontemplate providing a blading means and a protective cover forturbines, which is equally applicable to the rotor or stator element.

ln the drawings accompanying this application and forming a partthereof, Figure 1 is a fragmental transverse section through a turbineand discloses a portion of the rotating blade-carrying element, providedwith blades mounted in accordance with my invention, and a portion ofthe stationary blade-carrying element provided with directing vanesmounted in accordaace with my invention; Fig. 2 is a fragmentallongitudinal section of the rotor element of a turbine along the lineA-A of Fig. l; Fig. 3 is a fragmental plan view of the rotatingblade-carrying element and discloses-blades mounted in accordance withmy invention; Fig. 4 is a plan View of a portion of a base strip forminga detail of my invention; Fig. 5 is an end view of the strips shown inFig.

Specification of Letters Patent.

Application filed June 25, 1908.

Patented July 4, 1911. SeriaI No. 440,334.

4; and Fig. 6 is an elevation of a blade forming a detail of myinvention.

Throughout the remainder of the specilication and in the claims, I willdesignate both the rotating blades and the stationary directing vanes bythe broad term blades and I will employ the term blade-carrying elementto include both the rotating and the stationary blade-carrying elements.

My invention contemplates assembling the blades in segmental rings bypermanently and positively securing them in place on a segmental basestrip which is provided with a flange adapted to form a protective stripfor the turbine blade-carrying element, when the strip is mounted inplace on the element.

Referring to the drawings: The bladecarrying element 7 of the turbine isprovided with a plurality of undercut blademounting slots 8, in whichsegmental base strips 9 are mounted. The base strips are rolled or drawnto the desired section and are formed into semi-circular or smallersegmental sections of the same curvature as the blade-mounting slots inwhich they are to be mounted. Each strip is provided with a plurality ofsuitably spaced blade receiving slots 1l which extend radially acrossone lateral face of the strip 9 and are adapted to receive the bases ofthe blades l0 and to properly space and gage the blades.

A longitudinally extending and laterally projecting flange 12 is formedon each strip 9 flush with the outer peripheral face and, overhangingthe lateral face 13 of each strip, is adapted to project out of theblademounting slot in which the strip is mounted, and to lie in closecontact with the portion of the peripheral face of the blade-carryingelement 7 located between t-he slot 8 in which the strip is mounted andthe next adjacent mounting slot.

The blades 10 are substantially crescent shaped and are of the samecross section throughout their length. Each notch 1l conforms at itsinner end to the contour of a portion of each blade and is soconstructed as to lit about one-half of the base portion of each bladewhen one of its walls has been distorted to secure a blade in the nextadjacent notch. The bases of the blades are inserted one after the otherin consecutive notches and the projectingA wall of each notch, is, afterthe blade is in place, pressed into engagement with the base portion ofthe blade to thereby secure it to the base strip. After the blades arein place the walls of the notches, which are then lapped one over theother to inclose the blades, present a substantially plane face, whichmay be finished and trued up if desired.

In addition to the above described means for securing the blades to theblade-mounting strips, I have provided means for positively locking eachblade to its mounting strip.

A longitudinally extending slot 14 isv cut across the face 13 of eachstrip and extends deep enough into the strip to intersect the inneredges of the notches 11. Each blade l0 is provided, at one edge and nearits base, with a. notch 15` which is so located as to register with theslot 14 when the blade is in place in a blade-mounting notch 11. Afterall the blades are secured to a blade strip 9 by the frictionalengagement of the walls of the mount-ing slots 11, a locking wire 16 isinserted into the slot 14 and, engaging the notches 15 of each blade,permanently locks each blade to the strip and secures it againstlongitudinaLdisplacement.

The face 13 of each segmental strip is inclined to correspond to theinclination of the undercut walls of the blade-mounting slots 8. Eachwire 16 is of such size that it will be held in place within itsmounting slot 14 by contacting with the adjacent face of theblade-mounting slot 8 when the blade strip is located within a slot 8.

Other means may be employed for securing the wires 16 in place in theirmounting slots; for example, they may be soldered or pressed into placeso as to be permanentljT secured to the blade-mounting strip before itis located and secured in the blade-mounting slot. The bases of theblades may also be cutor swaged at their mounting ends so as to morereadily be secured into the mounting notches 11. v

The outer or free end of each blade is pro- .vided with a comma-shapedhole 18 through which a binding wire 19, of comma-shaped cross sectionextends. The binding wire is secured in place by shearing, on each sideof each blade, and by bending over, between adjacent blades, alongitudinally extending rib 20, which is formed integrally with thewire 19. The bent over portions of the rib 2O form spacing pieces whichare secured to the main body portion of the wire and which positivelylock the outer ends of the blades in their proper relative positions,the

Y main body portion of the wire acting as binding element for theblades.

j After the blades are in place, the segmental strips are located in theblade-carrying element and secured thereto as follows:

Each base strip is introduced into a blademounting slot so that itsinclined face 13 contacts with one of the undercut walls of the slot,and the projecting flange 12 contacts with the peripheral face of thebladecarrying element.

Any suitable means may be employed for securing the blade strips intothe blademounting slots, but since each of the lateral walls of eachblade-mount-ing slot is undercut, I preferably employ compound taperedwedges 22 to secure the blade strips into the slots. The wedges areintroduced into the slot in pairs, one beside the other, between theblade strip and one undercut wall of the slot. The wedges are soconstructed that, when driven home, the two wedges of each pairconjointly form a wedge shaped key, which effectively secures the bladestrip in place within the .slot and which is prevented, by its shape andthe shape of its component wedges, from being dislodged from the slot bycentrifugal or other dislodging forces.

Each segmental strip is secured in place by a number of pairs of wedges22 suitably spaced along the strip. It is preferable, however, to sospace the wedges that the ends of the component wedges of one pair abutagainst the ends of the wedges of the next adjacent pair and therebysecure them against longitudinal displacement.

It is necessary on account of the construetion of the blade-mountingslots and component wedges to leave considerable space between the firstand last pairs of wedges introduced into the blade-mounting slot and forthat reason some suitable means is employed for securing the componentwedges of the first and last pairs int-reduced into the slot againstlongitudinal motion.

In the drawings I have disclosed the blade-mounting strips provided withflanges 12 of such width that the flange of one strip not only coversthe portion of the peripheral face of the blade-mounting elementintermediate the slot S, in which the strip is mounted, and the nextadjacent slot, but also projects into close proximity with the nextadjacentv row of blades and covers the wedges 22. It may be founddesirable to employ narrower anges 12 so that the blade-mounting wedges22 are not covered but are at all times accessible. IlVith eitherconstruction the blade-mounting elements are adequately protected fromthe erosive and corrosive action of the motive Huid and the water ofcondensation traversing the j working passages of the turbine.

I have shown, in the drawings deeper notches 15 in the blades mounted tothe rotor of the turbine than in the blades mounted on the stator of theturbine. The depth of these notches, however, may be varied to suit theconditions, provided, of course that the Wire 16 is of such section thatit Will be held securely in its mounting slot let by the adjacent Wallof the blade-rnounting slot, when the strip is in place in a blademounting slot.

In accordance with the provisions of the patent statutes, I havedescribed the principle of my invention, together with the apparatuswhich I novv consider to represent the best embodiment thereof, but Idesire to have it understood that the apparatus shown is onlyillustrative and that the invention can be carried out by other means.

What I claim is:

l. In a turbine, a blade strip provided With blade-receiving notches,blades in said notches and a longitudinally extending locking meansbearing against the blades and against the strip on the side opposite tothat on which the notches are provided.

2. In a turbine, a blade-carrying element provided With a slot, ablade-strip provided with blade-receiving notches, the Walls of thenotches frictionally engaging the blades, and a locking member extendinglongitudinally of the strip and bearing thereagainst on the sideopposite to that on Which the notches in the strip are provided.

3. A turbine blade-carrying element provided vvith a slot, a blade striphaving bladereceiving notches on one longitudinal edge, blades in saidnotches and frictionally engaged by the edges thereof, and a lockingWire engaging notches in the blade, said Wire being on the side ofthestrip opposite to that on Which the notches aiie provided.

4. In combination in a turbine, a plurality of blades, a blade stripprovided With blade receiving notches, the Walls of which are adapted togrip the bases of the blades by being pressed into gripping engagementtherewith, a locking member located in a slot provided in the strip vandengaging notches provided in each blade, and a laterally projectingflange formed integrally With each strip.

5. In combination in a turbine, a plurality of blades, a blade stripprovided With blade receiving notches, the Walls of Which are adapted toengage t-he bases of the blades by being distorted, and a Wire let intosaid strip and adapted to positively lock said blades thereto.

6. In a turbine, a plurality of blades, a blade strip provided for saidblades, and means for positively locking each blade to said strip andWithin the free edge of the strip.

7 In combination in a turbine, a plurality of blades, a base strip.therefor, to Which said blades are adapted to be secured, a protectivestrip formed integrally With said base strip, and means for positivelylocking said blades to said base strip.

8. A foundation strip for blading having notches to receive blades onone side and a flange on the opposite side adapted to eX- tend over theturbine element.

9. A foundation strip for blading having notches on one side and aprotective element on the opposite side.

10. A base strip for turbine blades having a flange projecting from onelongitudinal edge and notches for the reception of blades in theopposite edge.

ll. In a turbine, a blade strip, blades, and a Wire locked into theblade strip to fasten blades into said blade strip.

l2. In a turbine, a blade strip provided with blade receiving notches,blades in the notches, and a locking Wire.

In testimony whereof, I have hereunto subscribed my name this 22nd dayof June,

CHARLES E. SWEET. Witnesses:

CHARLES W. MCGHEE, E. M. MoCALLIsTER.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

